6.20.1 Settings in the files required for monitoring a LAN

(1) Specifying a LAN monitor definition file

You specify in a LAN monitor definition file the IP addresses of the check packet transmission targets for monitoring a LAN. If you monitor only the hbonding status, the LAN monitor definition file must be empty (0 bytes).

You must specify this file for each monitored target before you start HA Monitor. A LAN monitor definition file cannot be added, changed, or deleted while HA Monitor is running.

The file name to be specified is LAN-interface-name.conf. For LAN-interface-name, specify the switchbyfail operand value that was specified in the server environment definition. Specifying a period (.) at the beginning disables the file.

The following rules apply to creating LAN monitor definition files:

• One IP address or IP label must be specified per line.

  Make sure that each IP address you specify is the IP address of a permanently activated remote host (such as a router) connected to the network to which the monitoring-target LAN interface is connected. The IP address used in the local node cannot be specified. If you specify an IP label, it might take time to resolve the host name, so we recommend that you specify an IP address.

• If HA Monitor monitors the number of received packets, in addition to specifying the IP address of a remote host, always specify the IP address of the host on which the paired instance of HA Monitor runs.

• Comments cannot be specified in these files.

• The same IP address or IP label cannot be specified more than once.

• A tab, space, or end-of-line code that immediately precedes or follows an IP address or IP label is ignored.

• If HA Monitor monitors ping responses, you can specify 1 to 1,024 IP addresses or IP labels. If HA Monitor monitors the number of received packets, you can specify 2 to 1,024 IP addresses or IP labels.

• The end-of-line code must be placed at the file end (after the IP address or IP label on the last line).

If you specify IP labels in a LAN monitor definition file, specify each IP address and the corresponding IP label in the /etc/hosts file.

You must not create in the directory for HA Monitor environment settings any file with the extension .conf other than a LAN monitor definition file.

An example of a LAN monitor definition file is shown below. In this example, the LAN interface name is eth0, the physical IP address is 192.168.0.1, and the network is 192.168.0.

File name: eth0.conf

192.168.0.2
192.168.0.3
192.168.0.4

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(2) Specifying a LAN monitoring script

Prepare this file if HA Monitor monitors a LAN by monitoring ping responses or the number of received packets. The name of the file to be set is lanpatrol.sh. If the monitored target is hbonding and only the hbonding status is to be monitored, there is no need to specify this file.

A sample is provided for this file under the directory for HA Monitor's sample files. Copy the sample file to the directory for HA Monitor environment settings and then use the copy. The following shows the contents of the sample file:

#!/bin/sh
#******************************************************************************
#*                                                                            *
#*    Linux(x86) HA Monitor                                                   *
#*    This is a sample of the LAN patrol command.                             *
#*                                                                            *
#*    [SYNOPSIS]                                                              *
#*        lanpatrol.sh interface [-r]                                         *
#*    [OPTIONS]                                                               *
#*        interface                                                           *
#*            The name of the LAN interface.                                  *
#*        -r                                                                  *
#*            Route monitoring method                                         *
#*    [DIAGNOSTICS]                                                           *
#*        0 : normal                                                          *
#*        1 : abnormal                                                        *
#*        2 : error                                                           *
#*                                                                            *
#*    All Rights Reserved. Copyright (C) 2011, 2018, Hitachi, Ltd.            *
#*                                                                            *
#******************************************************************************
#set -x

# retry interval(seconds) for receive packet number method. or
# return wait(seconds) of ping command for route monitoring method.
WAIT_TIME=3

# retry counter
RETRY=3

# environment variables
PATH=/usr/bin:/usr/sbin:/bin
export PATH

:
(Omitted)

Notes

Be careful if you create a LAN monitoring script with a sample file provided by HA Monitor whose version is earlier than 01-69. In this case, HA Monitor monitors the number of received packets independently of the setting of the lancheck_mode operand in the HA Monitor environment settings.

You can check the version of the sample file as follows:

• If the [OPTIONS] section does not include a description of the -r option, the version is earlier than 01-69.

• If the [OPTIONS] section includes a description of the -r option, the version is 01-69 or later.

The processing executed by this script differs depending on the monitoring method. The following shows the processing for each method.

If HA Monitor monitors ping responses:

Ping commands are issued in parallel for all IP addresses specified in the LAN monitor definition file by using the wait time specified (in seconds) in the WAIT_TIME environment variable. HA Monitor checks the return values from all ping commands that were issued in parallel, and if at least one of the return values is 0, HA Monitor judges that the LAN is in a normal state. If none of the return values is 0, HA Monitor retries issuing ping commands for all IP addresses specified in the LAN monitor definition file. The retry count can be set by using the RETRY environment variable. After all retries are completed, if none of the return values is 0, HA Monitor judges that the LAN is in an abnormal state.

If HA Monitor monitors the number of received packets:

• The script issues the ping command to the IP address specified in the LAN monitor definition file.

• When the time specified (in seconds) for the WAIT_TIME environment variable passes, the script determines repetitively the number of packets received by the monitored LAN interface and then compares the current value with the previous value. If the numbers of packets received do not match, the script determines that the LAN is functioning normally.

  If they do match, the script retries issuance of the ping command and again determines the number of packets received. The number of retries can be set for the RETRY environment variable. If the number of packets received remains the same over all retries, the script determines that an error has occurred.

The command line to be specified in the LAN monitoring script differs depending on the monitoring method. The following shows the command line for each method.

If HA Monitor monitors ping responses:

lanpatrol.sh∆LAN-interface-name∆-r

If HA Monitor monitors the number of received packets:

lanpatrol.shΔLAN-interface-name

Legend:

Δ: Indicates a single-byte space.

You can edit the sample file, if necessary. The following subsections provide notes about the sample file when it is used as is and when it is edited.

lancheck_patrol operand value > LAN monitoring script execution time + 2

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